نشریه مدیریت شهری و مهندسی محیط زیست
پیاپی 3 (پاییز 1402)

Air pollution is recognized as one of the fundamental challenges in the field of environmental engineering. This study examines the impact of vehicle tires on air pollution and explores methods to reduce it. A significant portion of the energy generated by the vehicle engine is lost through tire rolling resistance. Consequently, reducing tire rolling resistance leads to decreased fuel consumption and, consequently, reduced air pollution. Modifying the formulation of tire tread compounds can be an effective approach to reducing tire rolling resistance. One proposed method for modifying the formulation is the addition of nanoparticles as fillers. In this research, the impact of adding varying amounts of nanosilica to the tire tread compound formulation, which is the main factor contributing to vehicular energy dissipation, has been investigated. The results indicate that the addition of nanosilica increases tire rolling resistance. Furthermore, the influence of tire thickness on its lifespan and rolling resistance has been examined, demonstrating an increase in rolling resistance over time. Additionally, necessary changes in the production process conditions and their impact on the mechanical properties and performance of the produced materials have also been investigated. Rheological analysis reveals that the addition of nanosilica leads to increased viscosity. Moreover, the examination of mechanical properties shows an increase in the modulus values of both 100% and 300% materials with the addition of nanosilica.

Due to the increasing importance of providing security services and measures to prevent and deal with fire incidents and crisis management in cities, fire stations are very important. Undoubtedly, the timely service of fire stations, more than anything else, along with the need to establish them in suitable places in urban environments, requires having the necessary capabilities and equipment to respond to the needs of citizens. Greater Tehran, with a population of more than eight million people, is the largest city in the country, due to the parallel expansion, and also the increase in population, has increased the grounds of fire in the city. The current research is important because its audience is all managers, and fire chiefs and it can be used to investigate management systems and accident command. The research method in this research is the hierarchical analysis process, where the indicators are compared and scored one by one, and the priority between them is determined. Based on the analysis conducted in this research, the operational forces stationed in the fire stations and operational vehicles are not proportional to the capacity of the region, and the firefighting equipment of these stations will not be sufficient for the region during the fires after the earthquake, and this is one of the negative points of the study area that during the earthquake Fire control is almost impossible and we will face a serious crisis.

The requirement to reduce production from the source of urban waste is to increase the participation of citizens. The method of educating citizens should be comprehensive and have a high penetration rate at the level of society as well as be economical. Distance education methods as one of the citizenship education methods can be taken into consideration by municipalities to promote the culture of waste reduction. In this study, an attempt is made to select the most appropriate and efficient distance education method for the use of Tehran municipality. In this regard, Khan's conceptual model has been used along with the Fuzzy Analytical Hierarchy Process. In this study, 100 questionnaires of paired comparisons, which were randomly collected from the 16th district of Tehran municipality, were used. The results of the prioritization model show the use and development of mobile educational applications as the most preferred option. Based on the interviews conducted with the citizens of District 16 of Tehran municipality, the strengths and reasons for choosing this option have been explained. In order to compare different types of remote education methods, 25 criteria in 8 proposed categories were used in the form of Khan's conceptual model, which was able to integrate the concepts and basis of a standard and successful remote education system in the fuzzy decision model.

In recent years, research on the widespread use of biodegradable polymers, such as sodium alginate (SA), in removing pollutants from water sources has shown significant growth. The present study aims to evaluate the efficiency of SA hydrogels cross-linked with ferric chloride (for mechanical strength) in optimizing the removal of nickel (Ni) from aqueous solutions. Various factors, including Ni initial concentration, solution pH, amount of adsorbent, and contact time, were considered using response surface methodology (Box-Benken model). Based on the results of FTIR and SEM analyses, activated SA hydrogels were found to have hydroxyl and carboxyl functional groups, and their surface morphology was non-flat and prominent. The Ni removal values in the presence of SA hydrogels varied, with the minimum and maximum removal percentages being 53.39% and 85.43%, respectively. Increasing the initial Ni concentration resulted in a decreasing trend in Ni removal, while increasing contact time, solution pH, and amount of adsorbent led to an increasing trend in Ni removal. The evaluation of the data obtained from Ni removal using the Box-Benken model showed an accurate prediction (R2 higher than 0.98%) in optimizing Ni removal from aqueous solutions in the presence of SA. The possible mechanisms of Ni removal by SA hydrogel were identified as the formation of Van der waals bonds (physical adsorption), interaction with carboxylate anions, chelate formation between Ni ions and hydroxyl functional groups, and electrostatic interactions (due to the negative surface charge of SA). Overall, the results of this study demonstrate that SA has a suitable ability to remove Ni from aqueous solutions. However, future studies should investigate, compare, and integrate other activation methods, such as physical activation (combination with inorganic substances) and chemical activation (surface grafting) on the SA polymer, to improve the removal efficiency of heavy elements using this polymer.

The location of city service units such as fire stations in urban areas is always one of the issues of municipalities that should be investigated and determined very carefully. The effectiveness of service quality and efficiency of fire stations is highly dependent on their proper location. Therefore, in this study, an attempt is made to determine the appropriate place to use for the establishment of a fire station by examining location information in district 16 of Tehran municipality (Nazi Abad district). For this purpose, 8 indicators affecting the location of the station were determined. The Fuzzy Analytic Hierarchy Process was used in order to prioritize them and determine the weight of their effect. Then spatial information of each of the indicators for the studied area were prepared in ARCGIS and discussed. Finally, by combining the maps, suitable places to establish a fire station with maximum efficiency were determined. According to the results, the southern strip and a part of the northern area of the investigated area are completely suitable for building a fire station. There is no possibility to build a fire station in the northwest and west side of the area due to its usage. Also, the eastern and northeastern sides have a similar situation.

The environmental risk of the supply chain in the electricity industry is of great importance due to the many indicators and the extent of this industry. The expansion of the supply chain and the amount of fossil fuels consumed in this industry increases the importance of studies based on sustainability and compatible with the environment. As a result, the proper recognition and prioritization of the criteria affecting the green supply chain will greatly help the planners and operators of the electricity industry in order to reduce the environmental risk. In this study, an attempt is made to evaluate and investigate the risk of sustainable environmental supply chain using fuzzy hierarchical analysis (Cheng's method) in Iran's power plant industry. In this regard, 19 indicators were identified, collected and proposed based on interviews and review of past studies. Using the hierarchical analysis model in the fuzzy space and the opinions of 10 industrial and academic experts, the criteria were compared two by two and finally prioritized. According to experts, the modification of the price of energy carriers will have the greatest impact and the use of towers and masts with greater height will have the least impact on the risk of the sustainable environmental supply chain in Iran's power plant industry.